Surgical variables and risk factors associated with urinary leak following partial nephrectomy: Insights from a high-risk population.

604 Background: Urinary leak (UL) is a common complication following partial nephrectomy (PN). This study aims to identify the risk factors and surgical variables associated with the development of UL following PN in a cohort that includes a significant number of patients with hereditary renal cancer syndromes, multiple tumors, and a history of prior PNs. Methods: A retrospective chart review was conducted to identify patients who underwent PN at our institution from January 2006 to December 2023. Clinical, demographic, and surgical characteristics were recorded and analyzed. Statistical analysis was performed with SPSS v.29.0. Results: A total of 1173 PNs were analyzed, of which 89 (7.6%) had a UL. Patients had a median age at time of surgery of 50 [Interquartile range (IQR): 38 - 59] years, and 3 [IQR: 1 - 6] tumors removed per procedure. The robotic approach was utilized in 61.6% of cases, and the most common diagnosis was von Hippel-Lindau disease (47.4%). The frequency of UL was 5.1% for first-time PN, 10.4% for second, and 19.6% for third. Multivariable-adjusted analysis demonstrated an increased risk of UL with 3 rd PN (OR 2.379; p = 0.013), higher intraoperative estimated blood loss (per 100mL: OR 1.016; p = 0.006) and a decreased risk with robotic approach (OR 0.376; p < 0.001). (Table) Overall, 98.9% of UL cases (88 patients) were successfully managed with conservative management (post-op drain and foley), ureteral stent placement, percutaneous drain, or nephrostomy tube. Conclusions: In this cohort, UL is associated with the complexity of the surgery (repeat PN and higher EBL). A robotic approach had a lower risk of UL, while all but one UL were effectively managed non-operatively. Future research should investigate intraoperative and postoperative strategies to minimize this complication. Multivariable-adjusted logistic regression analysis evaluating the association between clinical variables and urinary leak after partial nephrectomy.* OR 95% CI p-value Partial nephrectomy count 1 1 2 1.693 0.973 - 2.944 0.062 3 2.379 1.200 - 4.714 0.013 ≥ 4 1.121 0.326 - 3.848 0.856 Surgical approach Open 1 Laparoscopic 0.324 0.042 - 2.517 0.281 Robotic 0.376 0.225 - 0.631 < 0.001 EBL (per 100 mL) 1.016 1.004 - 1.028 0.006 CI: Confidence interval, EBL: Estimated blood loss, OR: Odds ratio. *Analysis conducted using variables listed as well as age, gender, kidney laterality, race, ethnicity, presence of solitary kidney, surgical technique, total number of tumors removed, and size of largest tumor removed.